Formula to Calculate Average increase

[hblbs]

Is there a formula to calculate the average daily increase/decrease in sales from the previous day? Like in the example below.

<TABLE borderColor=#05ad00 cellSpacing=1 cellPadding=2 width=233 border=1><TBODY><TR><TD width="13%" height=16>

Day​

​

​

</TD><TD width="29%" height=16>

Sales​

​

​

</TD><TD width="29%" height=16>

Increase​

​

​

</TD><TD width="29%" height=16>

Average​

​

​

</TD></TR><TR><TD width="13%" height=16>

1​

​

​

</TD><TD width="29%" height=16>

10​

​

​

</TD><TD width="29%" height=16>
</TD><TD width="29%" height=16>

22.5​

​

​

</TD></TR><TR><TD width="13%" height=16>

2​

​

​

</TD><TD width="29%" height=16>

20​

​

​

</TD><TD width="29%" height=16>

10​

​

​

</TD><TD width="29%" height=16>
</TD></TR><TR><TD width="13%" height=16>

3​

​

​

</TD><TD width="29%" height=16>

30​

​

​

</TD><TD width="29%" height=16>

10​

​

​

</TD><TD width="29%" height=16>
</TD></TR><TR><TD width="13%" height=16>

4​

​

​

</TD><TD width="29%" height=16>

80​

​

​

</TD><TD width="29%" height=16>

50​

​

​

</TD><TD width="29%" height=16>
</TD></TR><TR><TD width="13%" height=16>

5​

​

​

</TD><TD width="29%" height=16>

100​

​

​

</TD><TD width="29%" height=16>

20​

​

​

</TD><TD width="29%" height=16>
</TD></TR></TBODY></TABLE>

 

[Ruddles]

Assuming the word "Day" is in cell A1, place this in D3:-

=SUM(C$2:C3)/(A3-A$2)

Then copy it down.

Is that what you're looking for?

(The first calculation would have to be on Day 2, no?)